Kate Vows to Sleep on the Streets to Aid the Homeless: Report

London, like many cities in America, has a homelessness problem. But the British capital also has a goodwill ambassador America doesn't: the Duchess of Cambridge.

According to reports, Kate, 30, says she will join a British TV star – and maybe even sleep on the streets – in a "Sleep Out" public awareness campaign that will shed a light on the plight of London's homeless, actress and activist Lisa Maxwell tells the Mirror.

"She asked me about sleeping out, so I said: 'Next time I do it, you're doing it with me. No excuses,", Maxwell, 48, said, according to the newspaper.

Pointing out that Kate's husband, Prince William, is a patron of the Centrepoint charity (whose stated aim is to "give homeless young people a future"), Centrepoint ambassador Maxwell told Kate, " 'He's done it.' She said: 'You're on.' "

Maxwell also said it was William who first introduced her to his wife at a reception for Centrepoint – and that Maxwell finds Kate "very savvy and very smart."

But a spokesperson for William and Kate says reports of her sleeping on the streets are just not true.

"There are no plans for the Duchess to sleep out for Centrepoint," the spokesperson tells PEOPLE. "She doesn't have any official role with Centrepoint, but will obviously continue to support the Duke in his patronage of the charity."

As a Centrepoint patron (so was his mother, Princess Diana), William prepared for Christmas 2009 by sleeping with the homeless near Blackfriars Bridge – and reportedly nearly got run over by a streetsweeper.

At the time, reports the Mirror, Centrepoint chief executive Seyi Obakin wrote on the charity's website: "He was determined to do it as patron to raise awareness of the problem and to be able to understand a little better what rough sleepers go through."

A St. James's Palace spokesperson said: "Prince William took away from the experience the importance of tackling all the issues that cause people to be homeless and stay homeless, from drug dependency to mental health problems."